I'm working on my Fort VeterHaven map, and I'm trying to create a nice frame for it. I'm attempting a trick I learned a while back, which is to increase the line width of the existing border, change the color to a bitmap fill, add bevels and glows (or what ever I chose), and whatever else I need to make the frame.

I've done this quite a few times, and it's worked pretty well.... but now I'm stumped, and I know it's probably something simple that I'm overlooking. But what I've ended up with, is two wide lines with a bitmap fill, and a white space in between. I want to combine the two, and turn it into one solid piece. I thought combine path would do it, but I was wrong. Path to poly didn't work either. What am I missing?

The reason this happens is that the map border here isn't just a sing line/path, but an actual polygon. You can see down in the left corner where the two ends of this long polygon meet.When you increase the line width of a polygon, it switches from being a filled entity, to being a polygon with a thick outline (like you see here), and the fill is applied to the line.

Instead of manipulating the existing borders, and relying on it being drawn a particular way for your technique to work, I recommend you use the Box command to draw a new rectangular entity yourself instead and manipulate that, that should give the desired result.